Windshield cleaning system



Oct. 19, 1954 J. R. OISHEI ETAL 2,692,079

WINDSHIELD CLEANING SYSTEM Original Filed March 8, 1947 2 Sheets-Sheet l A ORNEYJ 22 INVENTORS Oct. 19, 1954 J. R. OISHEI ET 'AL WINDSHIELD CLEANING SYSTEM 2 sheets -sheet 2 Original Filed March 8, 1947 iii N5 INVENTO R5 @yww ATTORNEYS Patented Oct. 19, 1954 UNITED STATES PATENT OFFICE WINDSHIELD CLEANING SYSTEM John R. Oishei, Buffalo, and Anton Rappl, Eg-

gertsville, N. Y., assignors to Trico Products Corporation, Buffalo, N. Y.

3 Claims. '1

This application is a division of our earlier Patent No. 2,520,650, August 29, 1950, the invention relating to a rotary pump of the kind comprising a cylindrical chamber in which a rotor is journaled for rotation about an eccentric axis, the rotor having radially movable impeller blades which slide in and out in contact with the wall of the encircling chamber as the rotor rotates.

It is the usual practice to operate the windshield cleaner and other accessories of a motor vehicle by a fluid pressure motor which i connected to the intake manifold of the vehicle engine for its suction supply, which has the disadvantage that, when the throttle is Wide open, the motor will slow down. In order to obviate this disadvantage, it has been proposed to supplement the manifold supply of suction with an auxiliary supply furnished by a pump of the reciprocating plunger type, air being drawn by the manifold through the pump chamber, when the pump was not required to operate. A rotary pump of the aforesaid type, which has certain advantages over the reciprocating type of pump, cannot however be used, because the presence of the impeller blades obstructs air flow through the pump chamber when the pump is at rest.

The primary object of the invention, therefore, is to enable a rotary pump of the kind set forth to be used for supplementing the suction induced by the engine intake manifold. Although the pump is primarily intended for the abovementioned purpose, namely for inclusion in an operating system for vehicle accessories, it may of course also be used for other purposes.

A further object of the invention is to provide a pump with a shunt passage connecting the pump inlet to the pump outlet in by-pass relation to the pump chamber, with a check valve acting to close the shunt passage when the pump is functioning, and to open the passage when a second source of pressure dominates to permit airflow from the inlet through the passage to the outlet.

The foregoing and other objects will manifest themselves as the following description progresses with reference to the accompanying drawings wherein:

Fig. 1 is a diagrammatic view showing the improved system;

Fig. 2 is an elevation of a rotary type pump incorporated therein;

Fig. 3 is a cross-sectional view through the p p;

Fig. 4 is a sectional view of the system control, with the windshield cleaner motor in fragment; and

Fig. 5 is a sectional view of a pressure switch employed.

Referring more particularly to the accompanying drawings, the numeral i designates the windshield of a motor vehicle, 2 the wiper of the windshield cleaner, 3 the wiper actuating arm, and 4 the arm actuating shaft which may also constitute the shaft of the cleaner motor 5. Fixed to the shaft t within the motor chamber is a piston-like vane 6 which oscillates therein as the pressure differential is timely reversed by automatic valve mechanism 7 and is ultimately held arrested against a seat 8 when the control valve 9 is moved by its handle I!) to park the wiper. All of this is more clearly depicted in an earlier Patent No. 1,978,634, the cleaner motor being connected to the intake manifold l I of the vehicle engine by a conduit l2.

As an alternate source of suction supply there is provided a pump i3 which is interposed in the suction line l2 by having its inlet M connected to the cleaner motor and its outlet 10 joined to the intake manifold. The pump is designed to be driven by an electric motor it which is connected by wiring ii! in circuit with a source of electrical energy it and also with a pressure responsive switch i9. This switch is connected into the suction line [2 between the manifold and the pump for closing the pump circuit whenever the manifold pressure becomes deficient. To this end it may comprise simply a contact plate 20 urged to a position for bridging the spaced contacts 2! by a spring 22 but adapted to be withdrawn from such circuit closing position-by the manifold suction when the latter is sufficient for practical cleaner operation. To facilitate its installation the pressure switch may be carried the pump for being mounted as a unit therewith. The cleaner system is conditioned for this pressure maintaining operation by a manual switch 23 which preferably is closed concurrently with the turning on of the cleaner motor. Thus, a switch contact plate it is fixed upon the valve handle it but insulated therefrom by a strip 25, and this plate is adapted to wipe across and bridge the gap between the spaced contacts 26 that are arranged on an insulated body member 2?. The body member may be fixedly supported on the valve guiding screws 20, while the valve pressure spring 20 may react to hold the bridging plate 2t upwardly against the contacts 26.

With this arrangement it will be apparent that whenever the valve 0 is shifted to cause the wiper motor to operate the pump switch 24, 20 will be closed. Therefore, the windshield cleaner will always respond to the manipulation of the control handle and always at the predetermined practical speed of operation.

The pump employed as the alternate source of supply is of the highly efficient rotary type where the air displacing rotor moves continually in the same direction of rotation. As herein illustrated, the pump comprises a casing having a: chamber 30 in which a rotor 3| is journaled for rotation about an eccentric axis. Radially movable impeller blades 32 slide in and out as they wipe the encircling chamber wall. The inlet passage I4 is joined by bore 33 to a recess 34 in an end wall 35 of the casing. The outlet passage 15 is likewise joined by a bore 36 to a recess 31 in such end wall. The two recesses open into the rotor chamber 30 at opposite sides of the lineof tangency between the periphery of the rotor and the encircling wall of the chamber. Because of this tangential line of sealing contact, together with the sealing engagement of the blades with the chamber walls, the intake side of the pump is sealed from the exhaust side as the impeller blades move in their circular path. Consequently, when the pump is at rest, a manifold-induced air stream is prevented from flowing through the rotor chamber. Therefore, special provision is made for such manifold-induced air flow to shunt or bypass the rotor chamber. Accordingly, the inlet and outlet passages l4 and 15 are joined by a shunt passage 38 which is normally closed by a check valve 39 when the pump is functioning either predominantly or solely as the source of operating pressure, the check valve being urged to its seat through the medium of a spring 40.

In this connection it will be noted that the pump casing is provided with an upstanding partition wall 4! between the inlet and outlet ports l and I6, such partition wall serving to define a valve chamber 42 about the inlet port and an outlet chamber 43 about the outlet port, both chambers being open at one side. A closure plate 44 is seated upon the casing to close both chambers 42, 43 and when in position provides abacking support for the spring 40 and serves to confine the valve 39. to its chamber. The closure plate may also serve to support the pressure responsive switch 19 within the outlet chamber 43. The removal of the closure gives access to both chambers. A duct 45 establishes communication between the two chambers and constitutes a part of the passage 38. This chamber formation enables the pump casing to be diecast for greater economy.

From the foregoing it will appear that the improved pump will function whenever the manifold supply is either deficient or absent, as when the engine has stopped. The pump is preferably connected to the electric motor to rotate at its high R. P. M. The degree of suction will therefore be high and may be predetermined to insure a practical cleaning speed for the wiper. The high speed rotary pump will respond promptly to afford an adequate supply for maintaining a constant and satisfactory cleaner operation.

The rotary pump with its valved shunt passage which establishes connection between the source of fluctuating suction or pressure and the windshield cleaner motor may be employed in combination with other air operated accessories on the motor vehicle.

The improved pump which may be designed for producing either negative or positive pressure retains the high degree of efiiciency of the rotary type of pump and enables its use with another source of pressure by which a. fluid movement may be maintained about the Pump cham- 4 her. While the bladed rotor is illustrated, it is not intended thereby to limit the style of pump since the inventive teaching herein may be incorporated'v in other pump embodiments without departing from the spirit. of the invention and the scope of the appended claims.

What is claimed is:

l. A pump comprising a casing having a pump chamber with inlet and outlet ports, said casing having an upstanding partition wall about the inlet port defining, a valve chamber open at one side, said" partition wall also defining an outlet chamber about the outlet port, said casing having a-duct connecting the valve chamber to the outlet chamber and constituting therewith a shunt passage connecting the: two ports in bypass relation to the pump chamber, a fluid displacing member operable in the pump chamber, a valve arranged in the valve chamber and confining fluid flow through the shunt passage from the inlet port to the outlet port; andv a removable closure wall means serving to close the second and third chambers and to confine the valve within its chamber.

2. A pump comprising a casing having a pump chamber with inlet and outlet ports, said casing having an upstanding partition wall about the inlet port defining a valve chamber open at one side, said partition wall also defining an outlet chamber about the outlet port, said casing having. a duct connecting the valve chamber to the outlet chamber and constituting therewith a shunt passage connecting the two ports in bypass relation to the pump chamber, a fluid. displacing member operable in the pump chamber, a valve arranged in. the valve chamber and confining fluid flow through the shunt passage from the inlet port to the outlet port, a removable closure wall means serving to close the second and third. chambers and to. confine the valve within its chamber, and electric control means for the fluid displacing member including a pressure responsive switch carried by the closure wall means and communicating with the outlet chamber for responding to a predetermined pressure therein.

3. A pump comprising a. casing having a pump chamber with inlet and outlet ports, said casing having a valve chamber open at one side and communicating with the outlet port and constituting' therewith av shunt passage connecting the two ports in bypass relation to the pump chamber, a rotary fluid displacing member operable in the pump chamber, a valve arranged in the valve chamber and confining fluid flow through the shunt passage from the inlet port to the outlet port, a removable closure wall means serving to close the valve chamber and to confine the valve within. its chamber, a spring interposed between the valve and the removable closure wall means to yieldably holdv the valve operative, and electric control means for the fluid displacing member including a pressure responsive switch carried by the closure wall means and communicating with the outlet chamber for responding to a predetermined pressure therein.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,390,829 Smoot Sept. 13, 1921 2,291,424 Wichorek July 28,. 1942 2,492,075 Van Atta Dec. 20, 1949 FOREIGN PATENTS Number Country Date 23,487 Great Britain I911 

